This is a very good article on why you should write on Medium. I certainly see a lot of value in using Medium every day and have started moving my writings here. It is free, allows free form long writing, beautiful professionally done interface, easiest interface to write, wysiwyr (what you see is what you write) interface, and all for free.
About control, actually, you can fine tune the control on everything you write on Medium and that’s one more reason I like Medium. You can still keep all your writing in your own blog or even in Evernote for that matter and pull in Medium all the writing you want. Medium is about spreading your ideas the way I see it, and I mighty started loving it.